In the past, NMR detectors have been used to provide NMR LipoProfile® lipoprotein panel reports. The NMR detectors have been located in a central testing facility with on-site support. The LipoProfile® report, available from LipoScience, Inc., located in Raleigh, N.C, is a lipoprotein test panel that assesses a patient's risk of coronary artery disease (“CAD”) and provides NMR-derived (quantitative analysis) lipoprotein measurement average low-density lipoprotein (LDL) particle size as well as LDL particle number, the latter representing the concentration or quantity (in concentration units such as nmol/L), and the former representing the average size of the LDL particles (in nm units) making up the LDL in the sample. HDL and VLDL subclass measurements can also be provided. See www.liposcience.com and U.S. Pat. No. 6,576,471 for exemplary reports of particular lipoprotein subclass parameters; the contents of the patent are hereby incorporated by reference as if recited in full herein.
It is known that NMR spectroscopic evaluation techniques can be used to concurrently obtain and measure a plurality of different lipoprotein constituents in an in vitro blood plasma or serum sample, as described in U.S. Pat. No. 4,933,844, entitled Measurement of Blood Lipoprotein Constituents by Analysis of Data Acquired from an NMR Spectrometer to Otvos and U.S. Pat. No. 5,343,389, entitled Method and Apparatus for Measuring Classes and Subclasses of Lipoproteins, also to Otvos. See also, U.S. Pat. No. 6,617,167, entitled Method Of Determining Presence And Concentration Of Lipoprotein X In Blood Plasma And Serum and co-pending co-assigned U.S. Provisional Patent Application Ser. No. 60/513,795, entitled Methods, Systems and Computer Programs for Assessing CHD Risk Using Mathematical Models that Consider In Vivo Concentration Gradients of LDL Particle Subclasses of Discrete Size. The contents of all the above patents and patent applications are hereby incorporated by reference as if recited in full herein.
As is well known to those of skill in the art, NMR detectors include an RF amplifier, an NMR probe that includes an RF excitation coil (such as a saddle or Helmholtz coil), a cryogenically cooled high-field superconducting magnet and an enclosed flow path that directs samples to flow serially, from the bottom of the magnet bore to a predetermined analysis location in the magnet bore. The NMR detector is typically a high-field magnet housed in a magnetically (and/or RF) shielded housing that can reduce the magnetic field level that is generated to within a relatively small volume. NMR detectors are available from Varian, Inc., having corporate headquarters in Palo Alto, Calif. and Bruker BioSpin, Corp., located in Billerica, Mass.
In operation, to evaluate the lipoproteins in a blood plasma and/or serum sample, the operator places the patient samples in a sample tray and an electronic reader correlates the sample to a patient, typically using a bar code on the sample tray. The sample is aspirated from the sample container and directed to flow through the flow path extending through the NMR detector. For detailed lipoprotein analysis, the NMR detector may analyze the sample for 1-5 minutes to determine amplitudes of a plurality of NMR spectroscopy derived signals within a chemical shift region of the proton NMR spectrum. These signals are derived by deconvolution of the composite signal or spectrum and are compared to predetermined test criteria to evaluate a patient's risk of having or developing coronary artery or heart disease.
In the past, a plurality of NMR spectrometers, all disposed at a central testing facility, have been used to carry out lipoprotein analysis on blood plasma samples to generate LipoProfile® test reports. The NMR spectrometers communicate with a local but remote computer (the computer is in a different room from the spectrometers) to allow the remote computer to obtain NMR spectra and analyze the NMR spectra to generate the patient diagnostic reports with quantitative lipoprotein values. Unfortunately, an operator manually carries out adjustments to the equipment using a manually input quality control sample to adjust the line width. In addition, the sample handler does not communicate with the NMR spectrometer and is not capable of electronically notifying the system of handling problems. The NMR spectrometer systems are complex and typically require dedicated on-site experienced operational oversight.
In view of the above, there remains a need for improved NMR analyzers that may be used in high-volume quantitative clinical applications at one or more remote locations.